Ruby is the best version of Perl. You can do command line one-liners and full-on object-oriented (SmallTalk object model) readable, maintainable programs.
My impression 20 years ago was that Ruby is an interesting mix between Perl and Python. In principle there is little that differentiates Perl and Ruby in terms of how maintainable or not their code can be.
However the Ruby ecosystem wound up with a lot of modules contributed by people who had just moved to it from languages like Java. They overreacted to their new found freedom. The result is that between a poor testing story and questionable practices like "monkeypatching" (literally modules overwriting random methods in other modules) the Ruby ecosystem wound up with a lot of nasty gotchas. (There is a lot of, "f you load module A then B, it works, but module B then A and it doesn't.")
Yes, Ruby programmers get up in arms when you say that they have a poor testing story. But ask them whether by default they have actually run unit tests for everything installed on their system, and they have not. Ask them if they could run unit tests and they think they can. But those who I have watched try have found out the hard way how many unit tests were only written for the original author to run in the original environment, and can't easily be run in an automated way. By contrast the default for CPAN is that every module has had its unit tests run on every system it is installed in, and automated smoke tests ensure that modules have had their tests run on a wide variety of operating systems and versions of Perl.
The result is that random Ruby module X is generally less likely to be dependable than random Perl module Y. Which in turn means that in my experience significant Ruby code bases written by competent programmers top out at smaller than Perl, with worse maintenance stories.
That doesn't discount the fact that there has been a tremendous amount of unmaintainable Perl written by incompetent programmers. (Particularly during the wild dot com days.) But "maintainable" is NOT something that Ruby has a good story to tell about.